MUC DICH YEU CAU VACH DAU
== Tat ca cac kich thuoc cung nhu hinh giong chi tiet sau khi da duoc khai trien can phai duoc danh dau tren vat lieu (ton tam hoac thep hinh), de phuc vu cho cong viec gha cong, lap rap va kiem tra trong qua trinh thi cong, co so de tien hanh lay dau la cac so lieu duong mau ban ve tu bo pha phong dang, bo phan ky thuat cung cap
== tuy thuoc vai qua trinh che tao than tau co cac muc dich lay dau sau:
+ lay dau de gia cong chi tiet
+ lay dau de phuc vu cho viec che tao phan tong doan than tau
+ lay dau tren chi tiet phuc vu trong qua trinh kiem tra va sua chua
+ lay dau phuc vu cho qua trinh ha thuy
== KY THUAT CHUNG KHI LAY DAU
= Tat ca cac nguyen vat lieu truoc khi dua di lay dau phai duoc nan thang lam sach va son lot chong gi.
= kich thuoc cac chi tiet hoac ket cau duoc laydau phai dap ung so lieu da cung cap tu bo phan phong dang hoac tu phong ky thuat. sai lech cho phep khi lay dau duoc quy dinh san cho tung chi tiet.
= doi voi thep tam hoac cac phan doan can phai phai danh dau tai phia ma o do se co nhung ket cau lap sap vao, tru 1 so duong kiem tra dac biet. cac duong uon can danh dau ve phia lom de tranh ran nut tam khi tien hanh uon.
= tren cac chi tiet hoac ket cau phai lay du cac duong sau: duong ly thiet, duong kiem tra, duong bao chi tiet (ke ca luong du) duong bao lo khoet, tam cung tron, luong du, vi tri lap dat cac chi tiet ket cau phu, khung suon......
= tren tat ca cac chi tiet phai viet ki hieu mieu ta ro rang ve cac thong so sau: so ban ve, ki hieu mat thep, so tam thep, ton phan doan, tong doan noi lap dat chi tiet...
= mo thep phai danh bang mui dot va khoanh vung bang son dau.
= luong du 1 so ki hieu nhu (mui, lai, tren duoi, man phai, man trai...) va 1 so chi dan khac nhu cat tren thuyen khi viet ki hieu cac chi tiet phai dung son dau cham.
= doi voi cac truong hop san xuat cung luc nhieu chi tiet cho cac con tau khac nhau co the dung mau son de phan biet chi tiet nao thuoc con tau nao.
= nhung duong nao can thiet de lau trong suot qua trinh san xuat can phai danh dau bang mui dot, chieu sau cac mui dot ko duoc vuot qua 1 mm. khoang cach giua 2 mui dot lien tiep ko vuot qua tu 10--20 mm tai cho goc can quan trong.
= tai cac vi tri khac phai dot 1 vet tai goc va tai moi phia phai dot 1 lo.
= tuy thuoc vao qua trinh cong nghe che tao chi tiet va trinh tu lap rap ma ta xac dinh luong du va vi tri dat luong du. doi voi truong hop gia cong bang may bao hoac may phay thi luong du chi de bang chieu dai tam , nhung ko nho hon 3 mm va ko vuot qua 10 mm.
= khi lay dau cac duong net chi tiet kim loai bang day phan hoac mui vach thi chieu day day phan ko duoc qua 0.7 mm va chieu rong va chieu sau cua net vach ko vuot qua 0.3 mm
= truoc khi tien hanh lay dau nguoi tho phai kiem tra chieu dai chieu rong. nguoi tho phai lam quen voi ban ve voi duong va ban thiet minh cu cong nghe neu co.
= nguoi tho phai chuan bi day du dung cu nhu mui dot thuong, tinh tam, kiem tra, mieng kep, moc kep, van chuyen, can vach duong song song co the dieu chinh duoc, can vach song song co cac diem co dinh va cac dung cu thong thuong kac
